1. Field of the Invention
The present invention relates to a method for manufacture of a magnetic head adapted to perform a frame recording operation in an electronic still camera or the like.
2. Description of the Prior Art
In a conventional magnetic head designed for use in an electronic still camera or the like to record frames of still images on a video floppy disk, the track-to-track interval is as small as 40 microns or so for attaining a high recording density, so that the requisite for precision is rendered extremely strict. For the magnetic head having a frame recording capability, it has been customary heretofore to employ a thin film type where magnetic gaps are arrayed in a straight line on one substrate. Since two channels in such thin-film type magnetic head are formed simultaneously on a single substrate by the thin film forming technique, the advantage is achieved that a satisfactory in-line accuracy can be ensured between the two-channel gaps and the electromagnetic characteristics thereof are rendered uniform. Accordingly no phase deviation occurs between the magnetic gaps, and any loss derived from the phase deviation of recorded and reproduced signals can be eliminated. Furthermore, due to the application of a high-precision thin film forming technique, the dimensional precision is retained and a narrow track interval can be realized.
However, in such a conventional thin-film type magnetic head, there exist some drawbacks, viz., production cost is high because of the high precision thin film forming process, and the steps thereof are complicated causing an additional increase in the cost.
In an attempt to solve the above problems, it has been proposed to use a bulk-type magnetic head which is producible at a lower cost. This type, however, has a difficulty in arraying the magnetic gaps of individual head elements in a straight line with a high precision, so that the problems of in-line error and phase deviation are raised. Furthermore, it is necessary in the bulk-type magnetic head to wind coils therein, which raises a problem relative to the coil winding space, and a failure in development of a narrow track structure. With regard to the conventional magnetic heads proposed for solving the above problems, there is known one example as disclosed in Japanese Patent Laid-open No. 63 (1988)-231711.
In the above exemplary magnetic head, track-width limit grooves are formed in one magnetic core half or block to shape two magnetic-gap forming surfaces on a single plane, and the other magnetic core halves, prepared individually with coil grooves formed therein, are joined to each other in such a manner that the respective magnetic-gap forming surfaces are mutually connected, thereby producing a two-channel magnetic head.
In the magnetic head thus produced, the magnetic gaps are formed on a single plane, so that the in-line precision of the gaps can be enhanced. And since the mutually confronting portions of the other magnetic core halves with coil grooves formed therein are inclined in the direction to recede from each other, a wide interval can be obtained between the mutually confronting magnetic core halves to consequently ensure a sufficient space required for winding coils in the grooves.
However, in the above known magnetic head where the magnetic core halves on one side are joined to each other, there is a disadvantage with respect to its cross-talk characteristics. In addition, although a sufficient space can be ensured for winding coils, the coil grooves exist in the same direction and therefore the coil winding operation is somewhat intricate and difficult.